<!DOCTYPE html>

<head>
    <meta charset="UTF-8">
    <title></title>
    <style>
        #a1,
        #a2 {
            height: 100px;
            width: 100px;
            display: inline-block;

        }

        #a1 {
            background-color: red;
        }

        #a2 {
            background-color: green;
        }
    </style>
    <script src="jQuery-3.6.3.min.js"> </script>
    <script>
        $(function () {

            $("#a1").click(function () {
                var a = "你哦好" ;
                $("div").html(a);
       
            });


        })
    </script>
</head>

<body>
    <div id="a1"></div>
    <div id="a2"></div>

</body>

</html>